Periprosthetic bone plates

ABSTRACT

The present disclosure relates to bone plates that are configured for use with bones having periprosthetic fractures. For example, in the event that a proximal femur is fractured in an area that is adjacent to a prosthetic component, such as a femoral stem used in a hip replacement, the periprosthetic bone plates of the present invention may be used. In one exemplary embodiment, the periprosthetic bone plates include a periprosthetic zone having a plurality of central apertures and a plurality of outer apertures that are offset from the central apertures. The periprosthetic zone may further include a plurality of indentations, each indentation extending longitudinally between adjacent outer apertures to narrow a width of the bone plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication Ser. No. 61/223,318, entitled “Periprosthetic Bone Plates,”filed Jul. 6, 2009, the disclosure of which is hereby expresslyincorporated by reference herein in its entirety.

BACKGROUND 1. Field of the Invention

The present invention relates to bone plates, and more particularly, toperiprosthetic bone plates and methods for implanting the same.

2. Description of the Related Art

Bone plates are commonly used to secure adjacent sections of a fracturedbone together and to facilitate healing of the fractured bone. Such boneplates may be attached to the fractured bone using a plurality of bonescrews. For example, a surgeon may position a bone plate to extendacross a fracture line, and then the surgeon may secure the bone platein place by inserting a plurality of bone screws through apertures inthe bone plate and into the patient's bone. However, when fractures ofthe bone occur in areas adjacent to a prosthetic implant, such as afemoral stem, the prosthetic implant may block areas of the patient'sbone intended for the bone screws.

Periprosthetic bone plates are available for stabilizing a fracture inan area adjacent to a prosthetic implant. Such bone plates may includeoffset apertures for guiding bone screws into the bone. However, knownperiprosthetic bone plates suffer from certain disadvantages. First,known periprosthetic bone plates may be configured to direct unicorticalbone screws into areas of the bone adjacent to the prosthetic implant toavoid the prosthetic implant. Although unicortical bone screws may stopshort of the prosthetic implant to avoid interfering with and/ordamaging the prosthetic implant, unicortical screw anchorage is not asstrong as cancellous or bicortical screw anchorage, for example. Also,to accomplish a sufficient offset, known periprosthetic bone plates mayinclude flanges that protrude from the bone plate, with the offsetapertures extending through these flanges. However, the flanges maycatch onto and strip the patient's muscle tissue while the bone plate isbeing implanted.

SUMMARY

The present invention provides bone plates that are configured for usewith bones having periprosthetic fractures. For example, in the eventthat a proximal femur is fractured in an area that is adjacent to aprosthetic component, such as a femoral stem used in a hip replacement,the periprosthetic bone plates of the present invention may be used toaccommodate the prosthetic component. In one exemplary embodiment, theperiprosthetic bone plates include a periprosthetic zone having aplurality of central apertures and a plurality of outer apertures thatare offset from the central apertures. The periprosthetic zone mayfurther include a plurality of indentations, each indentation extendinglongitudinally between adjacent outer apertures to narrow a width of thebone plate.

According to an exemplary embodiment of the present invention, a boneplate is provided for use with a bone having a periprosthetic fracture.The bone plate has a longitudinal axis that extends from a first end toa second end of the bone plate. The bone plate includes: a bottomsurface configured to face the bone; a top surface opposite the bottomsurface; a first side wall and a second side wall joining the top andbottom surfaces; and a periprosthetic zone located at the first end ofthe bone plate. The periprosthetic zone includes a plurality of outerapertures that extend through the bone plate from the top surface to thebottom surface, the plurality of outer apertures offset from thelongitudinal axis in a direction perpendicular to the longitudinal axis,the first and second side walls undulating in the periprosthetic zonesuch that, along a first length of the bone plate and in a directionfrom the first end toward the second end of the bone plate, the firstside wall narrows inwardly toward the longitudinal axis as the secondside wall widens outwardly from the longitudinal axis, and along asecond length of the bone plate in the direction from the first endtoward the second end of the bone plate, the first side wall widensoutwardly from the longitudinal axis as the second side wall narrowsinwardly toward the longitudinal axis.

According to another exemplary embodiment of the present invention, abone plate is provided for use with a bone having a periprostheticfracture. The bone plate has a longitudinal axis that extends from afirst end to a second end of the bone plate. The bone plate includes: aplanar bottom surface configured to face the bone; a top surfaceopposite the bottom surface; a plurality of side walls joining the topand bottom surfaces; a plurality of outer apertures that extend throughthe bone plate from the top surface to the bottom surface, the pluralityof outer apertures offset from the longitudinal axis in a directionperpendicular to the longitudinal axis; and a plurality of indentationsin the side walls, each indentation extending longitudinally betweenadjacent outer apertures to narrow the bone plate in a directionperpendicular to the longitudinal axis of the bone plate.

According to yet another exemplary embodiment of the present invention,a method is provided for repairing a bone having a periprostheticfracture, the bone including a prosthetic component implanted therein.The method includes the step of providing a bone plate having alongitudinal axis that extends from a first end to a second end, thebone plate including a periprosthetic zone located at the first end ofthe hone plate, the periprosthetic zone including a plurality of outerapertures offset from the longitudinal axis in a direction perpendicularto the longitudinal axis, the plurality of outer apertures extendingthrough the bone plate substantially in parallel, the bone platenarrowing inwardly toward the longitudinal axis between adjacent outerapertures. The method also includes the step of securing the bone plateonto the bone by inserting a bone screw into one of the plurality ofouter apertures while avoiding the prosthetic component.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention itself will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is an elevational view of a portion of an exemplary bone plate ofthe present invention secured onto a fractured proximal femur, the femurhaving a femoral hip stem implanted therein;

FIG. 2 is a perspective view of the bone plate of FIG. 1;

FIG. 3 is a top plan view of the bone plate of FIG. 1;

FIG. 4 is an elevational view of the bone plate of FIG. 1;

FIG. 5 is an elevational view of a portion of the bone plate of FIG. 1secured onto the femur, the bone plate spaced apart from the femur witha spacer;

FIG. 5A is a cross-sectional view of the encircled portion of FIG. 5;

FIG. 6 is a cross-sectional view of a portion of the bone plate of FIG.1 showing an aperture in the bone plate;

FIG. 7 is a view similar to FIG. 6 showing a bone screw in the apertureof the bone plate and a locking cap;

FIG. 8 is a view similar to FIG. 7 showing the locking cap in theaperture of the bone plate, the locking cap securing the bone screw inan angled arrangement;

FIG. 8A is a cross-sectional view of the encircled portion of FIG. 8;

FIG. 9 is a view similar to FIG. 8 showing the locking cap in theaperture of the bone plate, the locking cap securing the bone screw in aperpendicular arrangement;

FIG. 9A is a cross-sectional view of the encircled portion of FIG. 9;

FIG. 10 is a perspective view of another exemplary bone plate of thepresent invention;

FIG. 11 is a top plan view of the bone plate of FIG. 10;

FIG. 12 is an elevational view of the bone plate of FIG. 10;

FIG. 13 is a top plan view of yet another exemplary bone plate of thepresent invention;

FIG. 14 is a top plan view of still yet another exemplary bone plate ofthe present invention;

FIG. 15 is a perspective view of a portion of still yet anotherexemplary bone plate of the present invention having a modulartrochanteric zone detached from the bone plate; and

FIG. 16 is a perspective view of a portion of the bone plate of FIG. 15,showing the modular trochanteric zone attached to the bone plate.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate exemplary embodiments of the invention and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

FIG. 1 depicts a patient's proximal femur 50 having proximal end 52, adistal end (not shown), and shaft 54 extending therebetween. Shaft 54 offemur 50 includes fracture 56. In the illustrated embodiment, aprosthetic component, specifically femoral stem 60 of a hip replacementsystem, is implanted into the patient's proximal femur 50. As shown inFIG. 1, fracture 56 in femur 50 is located adjacent to femoral stem 60.

As shown in FIG. 1, bone plate 100 is secured onto shaft 54 of femur 50to extend across fracture 56. Although bone plate 100 is described anddepicted herein as being secured onto a patient's femur 50, bone plate100 may be sized for securement onto a patient's tibia, fibula, humerus,radius, ulna, or another long bone.

Referring to FIGS. 2-4, bone plate 100 of the present invention isprovided for use on proximal end 52 of femur 50. Bone plate 100 isconfigured for use on a patient's left leg, although a mirror imageplate may be provided for use on a patient's right leg. Bone plate 100includes proximal end 102 and distal end 104. Proximal end 102 of boneplate 100 is configured to rest against proximal end 52 of femur 50,with bone plate 100 extending distally along shaft 54 of femur 50 andacross fracture 56 (FIG. 1). Bone plate 100 also includes longitudinalaxis 106 and side walls 108, 110, that extend from proximal end 102 todistal end 104 of bone plate 100. Rather than being a straight line,longitudinal axis 106 of bone plate 100 may have a slight bend toaccommodate the shape of the patient's bone.

Bone plate 100 further includes a first, exposed surface 112 and asecond, bone-facing surface 114 that span between side walls 108, 110.According to an exemplary embodiment of the present invention, and asshown in FIGS. 2 and 4, surfaces 112, 114, of bone plate 100 aregenerally planar to facilitate smooth insertion of the bone plate 100beneath muscle tissue of the patient. For example, as disclosed inco-pending U.S. patent application Ser. No. 12/683,962, entitled “APlate for the Treatment of Bone Fractures,” filed Jan. 7, 2010, thedisclosure of which is expressly incorporated by reference herein in itsentirety, exposed surface 112 of bone plate 100 may have a centralplanar region near longitudinal axis 106 in a cross-sectionperpendicular to longitudinal axis 106, and bone-facing surface 114 ofbone plate 100 may have outer planar regions near side walls 108, 110,in the same cross-section perpendicular to longitudinal axis 106. It iswithin the scope of the present invention that surfaces 112, 114, ofbone plate 100 may be contoured to the shape of femur 50 (FIG. 1). Forexample, as disclosed in the above-incorporated U.S. patent applicationSer. No. 12/683,962, bone-facing surface 114 of bone plate 100 mayinclude a concave region between the outer planar regions that isconfigured to wrap around femur 50.

To accommodate bones of different sizes, bone plate 100 may be providedin various sizes. For example, bone plate 100 may vary in length L alonglongitudinal axis 106 from approximately 245 mm to approximately 401 mm.According to an exemplary embodiment of the present invention, a set ofbone plates 100 may be provided in lengths of 245 mm, 285 mm, 324 mm,363 mm, and 401 mm, for example.

Bone plate 100 includes periprosthetic zone 120, non-periprosthetic zone122, and transition zone 124 located between periprosthetic zone 120 andnon-periprosthetic zone 122. As shown in FIG. 3, periprosthetic zone 120is located near proximal end 102 of bone plate 100 andnon-periprosthetic zone 122 is located near distal end 104 of bone plate100.

Bone plate 100 may progressively decrease in width W (between side walls108, 110) from periprosthetic zone 120, to transition zone 124, tonon-periprosthetic zone 122, as shown in FIG. 3. For example, bone plate100 may be about 25 mm wide in periprosthetic zone 120, about 16 mm widein transition zone 124, and about 14.5 mm wide in non-periprostheticzone 122.

Also, bone plate 100 may vary in thickness T (between exposed surface112 and bone-facing surface 114) across periprosthetic zone 120,transition zone 124, and non-periprosthetic zone 122, as shown in FIG.4. In an exemplary embodiment, the thickness T of bone plate 100 may begreatest in transition zone 124, with the thickness T of bone plate 100decreasing in both periprosthetic zone 120 and non-periprosthetic zone122. For example, bone plate 100 may be about 5 mm thick inperiprosthetic zone 120, about 5.7 mm thick in transition zone 124, andabout 4.8 mm thick in non-periprosthetic zone 122. Due to the variedthickness T of bone plate 100, the strength of bone plate 100 may varyacross its length L. For example, transition zone 124 of bone plate 100may be stronger than periprosthetic zone 120 and/or non-periprostheticzone 122 of bone plate 100.

As shown in FIG. 3, exposed surface 112 of bone plate 100 includes aplurality of concave scallops 126, 127, 128, of various sizes. Scallops126, 127, 128, are arranged along side walls 108, 110, of bone plate 100to narrow the thickness T (FIG. 4) of bone plate 100 and to control themechanical resistance of bone plate 100. For example, bone plate 100 maybe configured to bend along large scallops 128 to a greater extent thanalong small scallops 126. Each scallop 126, 127, 128, may have a maximumdepth along its corresponding side wall 108, 110, of bone plate 100,with each scallop 126, 127, 128, gradually decreasing in depth inwardlytoward longitudinal axis 106 of bone plate 100, as shown in FIG. 2.

Within periprosthetic zone 120, bone plate 100 includes a plurality ofcentral apertures 130 that are generally aligned along longitudinal axis106 of bone plate 100, as shown in FIG. 3. Bone plate 100 also includesa plurality of outer apertures 132, 134, positioned alongside centralapertures 130.

As shown in FIG. 3, outer apertures 132, 134, are horizontally offsete.g., medially/laterally offset, anteriorly/posteriorly offset) fromcentral apertures 130. For example, in the illustrated embodiment ofFIG. 3, outer apertures 132 are horizontally offset from adjacentcentral apertures 130 in the direction of arrow A, and outer apertures134 are horizontally offset from adjacent central apertures 130 in thedirection of arrow B. The center of each outer aperture 132, 134, may behorizontally offset from the center of the adjacent central aperture 130by approximately 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or more. In anexemplary embodiment, the center of each outer aperture 132, 134, ishorizontally offset from the center of the adjacent central aperture 130by approximately 7.5 mm, such that the centers of outer apertures 132,134, are horizontally offset front one another by approximately 13 mm.In certain embodiments, outer apertures 132 may be arranged in a firstrow that is generally parallel to central apertures 130, and outerapertures 134 may be arranged in a second row that is also generallyparallel to central apertures 130.

Also, as shown in FIG. 3, outer apertures 132, 134 are vertically offset(e.g., proximally/distally offset) from central apertures 130 and eachother. For example, in the illustrated embodiment of FIG. 3, outerapertures 132 are vertically offset from adjacent central apertures 130in the direction of arrow C, and outer apertures 134 are verticallyoffset from adjacent central apertures 130 in the direction of arrow D.The center of each outer aperture 132, 134, may be vertically offsetfrom the center of the adjacent central aperture 130 by approximately 5mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or more. By vertically offsettingouter apertures 132, 134, from central apertures 130 along arrows C, D,the width W of bone plate 100 may be reduced. If central apertures 130and outer apertures 132, 134, were all aligned in a directionperpendicular to longitudinal axis 106, on the other hand, bone plate100 would have to be sufficiently wide in this perpendicular directionto accommodate all three apertures 130, 132, 134.

According to an exemplary embodiment of the present invention, threeapertures 130, 132, 134, may be organized in a subset 136 that extendsdiagonally across bone plate 100, as shown in FIG. 3. Bone plate 100 mayinclude a plurality of spaced-apart subsets 136 across its length. Incertain embodiments, the entire subset 136 of apertures 130, 132, 134,is vertically offset (e.g., proximally/distally offset) from theadjacent subset 136. Large scallops 128 may extend between adjacentsubsets 136, with small scallops 126 and medium scallops 127 extendinginto each subset 136, as shown in FIG. 3.

In certain embodiments, outer apertures 132, 134, may extend inwardlytoward longitudinal axis 106 from exposed surface 112 to bone-facingsurface 11.4 of bone plate 100, such that bone screws 150 (FIG. 1)located in outer apertures 132, 134, will point toward one anotherbeneath bone-facing surface 114 of bone plate 100. In other embodiments,outer apertures 132, 134, may extend substantially parallel to centralapertures 130, or even slightly outwardly from longitudinal axis 106,from exposed surface 112 to bone-facing surface 114 of bone plate 100.With central apertures 130 and outer apertures 132, 134, extending inparallel, bone screws 150 may be able to extend around even a largeimplant, like hip stem 60, as shown in FIG. 1. Thus, bone plate 100 maybe secured in place using bicortical or cancellous bone screws 150 thatextend around and beyond hip stem 60.

As shown in FIG. 3, side walls 108, 110, may undulate withinperiprosthetic zone 120. For example, side walls 108, 110 of bone plate100 may include concave indentations 140, with adjacent indentations 140forming apex 142 therebetween. Each indentation 140 may follow anarcuate path between each apex 142, reaching a maximum depth in boneplate 100 at base 144. The undulating pattern may increase in intensitytoward proximal end 102 of bone plate 100, with indentations 140increasing in length and/or depth toward proximal end 102 of bone plate100.

Along side wall 108 of bone plate 100, indentations 140 may extendbetween adjacent outer apertures 132, such that bone plate 100 widensenough at apex 142 to accommodate outer apertures 132 but narrowsbetween adjacent outer apertures 132. Similarly, along side wall 110 ofbone plate 100, indentations 140 may extend between adjacent outerapertures 134, such that bone plate 100 widens enough at apex 142 toaccommodate outer apertures 134 but narrows between adjacent outerapertures 134.

By vertically offsetting outer apertures 132, 134, from centralapertures 130, as discussed above, the width W of bone plate 100 may bereduced, because outer apertures 132, 134, may be bordered by at leastone indentation on the opposite side wall 108, 110 (e.g., side wall 108,110, opposite from apex 142). In an exemplary embodiment, the overallwidth W of bone plate 100 in periprosthetic zone 120, measured betweenapex 142 on side wall 108 and apex 142 on side wall 110, is about 25 mm.However, at any one point along longitudinal axis 106, such as betweenapex 142 on side wall 108 and base 144 on side wall 110, the width W ofbone plate 100 in periprosthetic zone 120 may be about 3 mm, 4 mm, or 5mm less, such as about 21 mm. The width W of bone plate 100 withinperiprosthetic zone 120 may reach a minimum along central apertures 130,because central apertures 130 may be bordered by indentations 140 alongboth side walls 108, 110. The smooth shape of side walls 108, 110, andthe narrow width W of bone plate 100 within periprosthetic zone 120facilitate smooth insertion of bone plate 100 beneath the muscle tissueof the patient.

According to an exemplary embodiment of the present invention, in adirection perpendicular to longitudinal axis 106, each apex 142 isaligned with an opposing base 144, as shown in FIG. 3. Therefore, whenone side wall 108 of bone plate 100 reaches a maximum width at apex 142,the other side wall 110 of bone plate 100 reaches a minimum width atbase 144. In this embodiment, indentations 140 on opposing side walls108, 110, may cooperate to maintain a substantially constant width W ofbone plate 100 within periprosthetic zone 120. This simultaneous,opposite behavior of side walls 108, 110, further facilitates smoothinsertion of bone plate 100 beneath the muscle tissue of the patient.When bone plate 100 is implanted, side walls 108, 110, will slide acrossthe patient's muscle tissue. As side wall 108 gradually widens towardapex 142, side wall 108 will extend deeper and deeper into the muscletissue along side wall 108. At the same time, side wall 110 willgradually narrow toward base 144 and gradually free itself from themuscle tissue along side wall 110. Resistance from muscle tissue alongside wall 108 may force bone plate 100 back toward the muscle tissuealong side wall 110, thereby reducing the risk of shredding the muscletissue along side wall 108. This cooperation between side walls 108,110, continues along the length of periprosthetic zone 120.

Like periprosthetic zone 120, non-periprosthetic zone 122 and transitionzone 124 of bone plate 100 may include a plurality of central apertures130 that are generally aligned along longitudinal axis 106 of bone plate100. However, unlike periprosthetic zone 120, non-periprosthetic zone122 and transition zone 124 may not require outer apertures 132, 134.For this reason, bone plate 100 may be narrower in non-periprostheticzone 1122 and transition zone 124 than in periprosthetic zone 120, asshown in FIG. 3.

In operation, and as shown in FIGS. 1 and 2, a surgeon may secure boneplate 100 onto the patient's femur 50 using bone screws 150 withoutinterfering with and/or damaging hip stem 60. In proximal end 52 offemur 50 adjacent to hip stem 60, the surgeon may offset bone screws 150from hip stern 60 by inserting bone screws 150 into outer apertures 132,134, rather than central apertures 130, in periprosthetic zone 120 ofbone plate 100. For example, in the illustrated embodiment of FIG. 1,bone screws 150 may be anteriorly and/or posteriorly offset from hipstem 60. Because bone screws 1150 may be entirely offset from hip stem60, bone plate 100 may be secured in place using bicortical orcancellous bone screws 150, as shown in FIG. 1. Bicortical or cancellousbone screws 150 may strengthen the fixation between femur 50 and boneplate 100, while still avoiding hip stem 60. Rather than avoidingcentral apertures 130 in periprosthetic zone 120 of bone plate 100, itis also within the scope of the present invention that the surgeon mayinsert unicortical screws into those central apertures 130 that stopshort of hip stem 60. In the distal end (not shown) of femur 50 beneathhip stem 60, the surgeon may insert bicortical, cancellous, orunicortical bone screws 150 centrally into femur 50 by inserting bonescrews 150 into central apertures 130 in non-periprosthetic zone 122 andtransition zone 124 of bone plate 100. In this distal region of femur50, the surgeon will not risk interfering with and/or damaging hip stem60. Suitable cancellous bone screws may be about 4 mm in length, andsuitable bicortical bone screws may be about 5 mm in length.

According to an exemplary embodiment of the present invention, boneplate 100, and specifically periprosthetic zone 120 of bone plate 100,may be spaced apart from femur 50. For example, as shown in FIGS. 5 and5A, the surgeon may insert spacers 160 into unoccupied central apertures130 of bone plate 100 to elevate bone-facing surface 114 of bone plate100 off of femur 50. Spacers 1160 may be provided in various sizes, suchas 1 mm, 2 mm, and 3 mm in length, to alter the spacing between boneplate 100 and femur 50. Advantageously, spacing bone plate 100 apartfrom femur 50 may allow adequate blood flow to the periosteum of femur50, thereby facilitating healing of femur 50.

According to another exemplary embodiment of the present invention, boneplate 100 may accommodate polyaxial bone screws 150 in central apertures130, as well as in outer apertures 132, 134. Apertures 130,132, 134, maybe sized to receive bone screws 150 in a perpendicular arrangement, asshown in FIGS. 9 and 9A, or in an angled arrangement, as shown in FIGS.8 and 8A. In the angled arrangement of FIG. 8, bone screw 150 may beoffset up to 15 degrees in any direction from the perpendiculararrangement of FIG. 9. To maintain bone screw 150 in the desiredposition, the surgeon may insert locking cap 152 into the correspondingaperture 130, 132, 134, and onto bone screw 150. Advantageously,polyaxial bone screws 150 enable the surgeon to manipulate and positionbone screws 150 in the desired portion of femur 50 while avoiding hipstem 60 (FIG. 1), if necessary.

As shown in FIGS. 1 and 2, bone plate 100 may include wire apertures 164that are sized for receipt of cerclage wire 162 therethrough. Inoperation, before inserting bone screws 150 into femur 50, the surgeonmay initially secure bone plate 100 onto femur 50 by wrapping wire 162through apertures 164 of bone plate 100 and around femur 50.Alternatively, if the surgeon determines that femur 50 is not in theproper condition to receive bone screws 150, the surgeon may secure boneplate 100 onto femur 50 using wire 162 instead of bone screws 150.

Referring next to FIGS. 10-12, bone plate 200 of the present inventionis provided for use on a distal femur (not shown). Bone plate 200 isconfigured for use on a patient's right leg, although a mirror imageplate may be provided for use on a patient's left leg. Bone plate 200 issimilar to bone plate 100, with like reference numerals indicating likeelements.

Bone plate 200 includes periprosthetic zone 220, non-periprosthetic zone222, and transition zone 224 located between periprosthetic zone 220 andnon-periprosthetic zone 222. As shown in FIG. 11, periprosthetic zone220 is located near distal end 204 of bone plate 200 andnon-periprosthetic zone 222 is located near proximal end 202 of boneplate 200. Bone plate 200 also includes longitudinal axis 206 and sidewalls 208, 210, that extend from proximal end 202 to distal end 204 ofbone plate 100. Rather than being a straight line, longitudinal axis 206of bone plate 200 may have a slight bend to accommodate the shape of thepatient's bone.

In operation, distal end 204 of bone plate 200 is configured to restagainst the distal end (not shown) of femur 50, with bone plate 200extending proximally along shaft 54 of femur 50 and across fracture 56(FIG. 1). With periprosthetic zone 220 of bone plate 200 located atdistal end 204 of bone plate 200, the surgeon may avoid interfering withand/or damaging a prosthetic component implanted in the patient's distalfemur, such as a femoral stem of a knee replacement system (not shown).

Bone plate 200 further includes a first, exposed surface 212 and asecond, bone-facing surface 214 that span between side walls 208, 210.According to an exemplary embodiment of the present invention, and asshown in FIG. 10, surfaces 212, 214, of bone plate 200 are generallyplanar to facilitate smooth insertion of the bone plate 200 beneathmuscle tissue of the patient. For example, as disclosed in theabove-incorporated U.S. patent application Ser. No. 12/683,962, exposedsurface 212 of bone plate 200 may have a central planar region nearlongitudinal axis 206 in a cross-section perpendicular to longitudinalaxis 206, and bone-facing surface 214 of bone plate 200 may have outerplanar regions near side walls 208, 210, in the same cross-sectionperpendicular to longitudinal axis 206. It is within the scope of thepresent invention that surfaces 212, 214, of bone plate 200 may becontoured to the shape of femur 50 (FIG. 1). For example, as disclosedin the above-incorporated U.S. patent application Ser. No. 12/683,962,bone-facing surface 214 of bone plate 200 may include a concave regionbetween the outer planar regions that is configured to wrap around femur50.

To accommodate bones of different sizes, bone plate 200 may be providedin various sizes. For example, bone plate 200 may vary in length L alonglongitudinal axis 206 from approximately 238 mm to approximately 393 mm.According to an exemplary embodiment of the present invention, a set ofbone plates 200 may be provided in lengths of 238 mm, 278 mm, 316 mm,355 mm, and 393 mm, for example.

As shown in FIG. 11, exposed surface 212 of bone plate 200 includes aplurality of concave scallops 226, 227, 228, of various sizes. Scallops226, 227, 228, are arranged along side walls 208, 210, of bone plate 100to narrow the thickness T (FIG. 12) of bone plate 200 and to control themechanical resistance of bone plate 200. For example, bone plate 200 maybe configured to bend along large scallops 228 to a greater extent thanalong small scallops 226. Each scallop 226, 227, 228, may have a maximumdepth along its corresponding side wall 208, 210, of bone plate 200,with each scallop 226, 227, 228, gradually decreasing in depth inwardlytoward longitudinal axis 206 of bone plate 200, as shown in FIG. 10.

Within periprosthetic zone 220, bone plate 200 includes a plurality ofcentral apertures 230 that are generally aligned along longitudinal axis206 of bone plate 200, as shown in FIG. 11. Bone plate 200 also includesa plurality of outer apertures 232, 234, positioned alongside centralapertures 230.

As shown in FIG. 11, outer apertures 232, 234, are horizontally offset(e.g., medially/laterally offset, anteriorly/posteriorly offset) fromcentral apertures 230. The center of each outer aperture 232, 234, maybe horizontally offset from the center of the adjacent central aperture230 by approximately 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or more. In anexemplary embodiment, the center of each outer aperture 232, 234, ishorizontally offset from the center of the adjacent central aperture 230by approximately 7.5 mm, such that the centers of outer apertures 232,234, are horizontally offset from one another by approximately 13 mm. Incertain embodiments, outer apertures 232 may be arranged in a first rowthat is generally parallel to central apertures 230, and outer apertures234 may be arranged in a second row that is also generally parallel tocentral apertures 230.

Also, as shown in FIG. 11, outer apertures 232, 234 are verticallyoffset (e.g., proximally/distally offset) from central apertures 230 andeach other. The center of each outer aperture 232, 234, may bevertically offset from the center of the adjacent central aperture 230by approximately 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or more. Byvertically offsetting outer apertures 232, 234, from central apertures230, the width W of bone plate 200 may be reduced. If central apertures230 and outer apertures 232, 234, were all aligned in a directionperpendicular to longitudinal axis 206, on the other hand, bone plate200 would have to be sufficiently wide in this perpendicular directionto accommodate all three apertures 230, 232, 234.

According to an exemplary embodiment of the present invention, threeapertures 230, 232, 234, may be organized in a subset 236 that extendsdiagonally across bone plate 200, as shown in FIG. 11. Bone plate 200may include a plurality of spaced-apart subsets 236 across its length.In certain embodiments, the entire subset 236 of apertures 230, 232,234, is vertically offset (e.g., proximally/distally offset) from theadjacent subset 236. Large scallops 228 may extend between adjacentsubsets 236, with small scallops 226 and medium scallops 227 extendinginto each subset 236, as shown in FIG. 11.

In certain embodiments, outer apertures 232, 234, may extend inwardlytoward longitudinal axis 206 from exposed surface 212 to bone-facingsurface 214 of bone plate 200, such that bone screws 150 (FIG. 1)located in outer apertures 232, 234, will point toward one anotherbeneath bone-facing surface 214 of bone plate 200. In other embodiments,outer apertures 232, 234, may extend substantially parallel to centralapertures 230, or even slightly outwardly from longitudinal axis 206,from exposed surface 212 to bone-facing surface 214 of bone plate 200.With central apertures 230 and outer apertures 232, 234, extending inparallel, bone screws 150 may be able to extend around and beyond theknee implant. Thus, bone plate 200 may be secured in place usingbicortical or cancellous bone screws 150, while still avoiding the kneeimplant.

As shown in FIG. 11, side walls 208, 210, may undulate withinperiprosthetic zone 220. For example, side walls 208, 210 of bone plate200 may include concave indentations 240, with adjacent indentations 240forming apex 242 therebetween. Each indentation 240 may follow anarcuate path between each apex 242, reaching a maximum depth in boneplate 200 at base 244. The undulating pattern may increase in intensitytoward proximal end 202 of bone plate 200, with indentations 240increasing in length and/or depth toward proximal end 202 of bone plate200.

Along side wall 208 of bone plate 200, indentations 240 may extendbetween adjacent outer apertures 232, such that bone plate 200 widensenough at apex 242 to accommodate outer apertures 232 but narrowsbetween adjacent outer apertures 232. Similarly, along side wall 210 ofbone plate 200, indentations 240 may extend between adjacent outerapertures 234, such that bone plate 200 widens enough at apex 242 toaccommodate outer apertures 234 but narrows between adjacent outerapertures 234.

By vertically offsetting outer apertures 232, 234, from centralapertures 230, as discussed above, the width W of bone plate 200 may bereduced, because outer apertures 232, 234, may be bordered by at leastone indentation on the opposite side wall 208, 210 (e.g., side wall 208,210, opposite from apex 242). In an exemplary embodiment, the overallwidth W of bone plate 200 in periprosthetic zone 220, measured betweenapex 242 on side wall 208 and apex 242 on side wall 210, is about 28 mm.However, at any one point along longitudinal axis 206, such as betweenapex 242 on side wall 208 and base 244 on side wall 210, the width W ofbone plate 200 in periprosthetic zone 220 may be about 3 mm, 4 mm, or 5mm less, such as about 23 mm. The width W of bone plate 200 withinperiprosthetic zone 220 may reach a minimum along central apertures 230,because central apertures 230 may be bordered by indentations 240 alongboth side walls 208, 210. The smooth shape of side walls 208, 210, andthe narrow width W of bone plate 200 within periprosthetic zone 220facilitate smooth insertion of bone plate 200 beneath the muscle tissueof the patient.

According to an exemplary embodiment of the present invention, in adirection perpendicular to longitudinal axis 206, each apex 242 isaligned with an opposing base 244, as shown in FIG. 11. Therefore, whenone side wall 208 of bone plate 200 reaches a maximum width at apex 242,the other side wall 210 of bone plate 200 reaches a minimum width atbase 244. In this embodiment, indentations 240 on opposing side walls208, 210, may cooperate to maintain a substantially constant width W ofbone plate 200 within periprosthetic zone 220. This simultaneous,opposite behavior of side walls 208, 210, further facilitates smoothinsertion of bone plate 200 beneath the muscle tissue of the patient, asdiscussed above with respect to bone plate 100 (FIGS. 2-4).

Like periprosthetic zone 220, non-periprosthetic zone 222 and transitionzone 224 of bone plate 200 may include a plurality of central apertures230 that are generally aligned along longitudinal axis 206 of bone plate200. However, unlike periprosthetic zone 220, non-periprosthetic zone222 and transition zone 224 may not require outer apertures 232, 234.For this reason, bone plate 200 may be narrower in non-periprostheticzone 222 and transition zone 224 than in periprosthetic zone 220, asshown in FIG. 11.

In operation, and as shown in FIG. 11, a surgeon may secure bone plate200 onto the patient's distal femur (not shown) using bone screws 150(FIG. 1) without interfering with and/or damaging a prosthetic componentimplanted in the patient's distal femur, such as a femoral stem of aknee replacement system (not shown). In the distal end of femur 50adjacent to the knee implant, the surgeon may offset bone screws 150from the knee implant by inserting bone screws 150 into outer apertures232, 234, rather than central apertures 230, in periprosthetic zone 220of bone plate 200. Because bone screws 150 may be entirely offset fromthe knee implant, bone plate 200 may be secured in place usingbicortical or cancellous bone screws 150. Bicortical or cancellous bonescrews 150 may strengthen the fixation between femur 50 and bone plate200, while still avoiding the knee implant. Rather than avoiding centralapertures 230 in periprosthetic zone 220 of bone plate 200, it is alsowithin the scope of the present invention that the surgeon may insertunicortical screws into those central apertures 230 that stop short ofthe knee implant. Toward proximal end 52 of femur 50 above the kneeimplant, the surgeon may insert bicortical, cancellous, or unicorticalbone screws 150 centrally into femur 50 by inserting bone screws 150into central apertures 230 in non-periprosthetic zone 222 and transitionzone 224 of bone plate 200. In this proximal region of femur 50, thesurgeon will not risk interfering with and/or damaging the knee implant.

Like bone plate 100 (FIGS. 2-4), bone plate 200 may be configured toreceive spacers 160 (FIGS. 5 and 5A), polyaxial bone screws 150 (FIGS.6-9), and/or cerclage wire 162 (FIG. 1) for securing bone plate 200 ontofemur 50.

Referring next to FIGS. 13-16, bone plates 300, 400, 500, of the presentinvention are provided for use on proximal end 52 of femur 50 (FIG. 1),much like bone plate 100 described above with reference to FIGS. 2-4.Bone plates 300, 400, 500, are similar to bone plate 100, with likereference numerals indicating like elements.

Each bone plate 300, 400, 500, includes periprosthetic zone 320, 420,520, non-periprosthetic zone 322, 422, 522, and transition zone 324,424, 524, located between periprosthetic zone 320, 420, 520, andnon-periprosthetic zone 322, 422, 522. Unlike bone plate 100 (FIG. 2),each bone plate 300, 400, 500, further includes trochanteric zone 370,470, 570, that extends proximally beyond periprosthetic zone 320, 420,520. In operation, the surgeon is able to secure trochanteric zone 370,470, 570, of the corresponding bone plate 300, 400, 500, onto greatertrochanter 58 of femur 50 (FIG. 1) for added stability. In theillustrated embodiments of FIGS. 13-16, each bone plate 300, 400, 500,is ring-shaped in the corresponding trochanteric zone 370, 470, 570,such that bone plate 300, 400, 500, is able to wrap around greatertrochanter 58 of femur 50 with bone of femur 50 protruding therethrough,as necessary.

As shown in FIGS. 13 and 14, each trochanteric zone 370, 470, may beintegrally formed with periprosthetic zone 320, 420, of thecorresponding bone plate 300, 400. Alternatively, and as shown in FIGS.15 and 16, trochanteric zone 570 may be removably coupled toperiprosthetic zone 520 of the corresponding bone plate 500 usingsuitable fasteners, such as screws 572. In this modular embodiment ofFIGS. 15 and 16, bone plate 500 may be used with or without trochantericzone 570 attached thereto.

Additional information regarding the bone plates of the presentinvention may be found in the above-incorporated U.S. patent applicationSer. No. 12/683,962.

Additional information regarding methods and tools for implanting thebone plates of the present invention may be found in U.S. patentapplication Ser. No. 12/683,953, entitled “Bone Plate Fixation System,”filed Jan. 7, 2010, the disclosure of which is hereby expresslyincorporated by reference herein in its entirety.

While this invention has been described as having a preferred design,the present invention can be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

What is claimed is:
 1. A bone plate for use with a bone having aperiprosthetic fracture, the bone plate having a longitudinal axis thatextends from a first end to a second end of the bone plate, the boneplate comprising: a bottom surface configured to face the bone; a topsurface opposite the bottom surface; a first side wall and a second sidewall joining the top and bottom surfaces; and a periprosthetic zonelocated at the first end of the bone plate, the periprosthetic zonecomprising a plurality of outer apertures that extend through the boneplate from the top surface to the bottom surface, the plurality of outerapertures offset from the longitudinal axis in a direction perpendicularto the longitudinal axis, the first and second side walls undulating inthe periprosthetic zone such that, along a first length of the boneplate and in a direction from the first end toward the second end of thebone plate, the first side wall narrows inwardly toward the longitudinalaxis as the second side wall widens outwardly from the longitudinalaxis, and along a second length of the bone plate in the direction fromthe first end toward the second end of the bone plate, the first sidewall widens outwardly from the longitudinal axis as the second side wallnarrows inwardly toward the longitudinal axis.
 2. The bone plate ofclaim 1, further comprising a plurality of central apertures that extendthrough the bone plate from the top surface to the bottom surface, theplurality of central apertures located along the longitudinal axis ofthe bone plate.
 3. The bone plate of claim 2, wherein the plurality ofcentral apertures continue to the second end of the bone plate.
 4. Thebone plate of claim 2, wherein the plurality of outer apertures areoffset from the central apertures in a direction parallel to thelongitudinal axis of the bone plate.
 5. The bone plate of claim 2,wherein the plurality of outer apertures are arranged in twolongitudinal rows, a first longitudinal row extending along a first sideof the central apertures and a second longitudinal row extending along asecond side of the central apertures opposite the first side.
 6. Thebone plate of claim 1, wherein each of the first and second wallsinclude a plurality of indentations in the periprosthetic zone, eachindentation extending longitudinally between adjacent outer apertures tonarrow the bone plate in a direction perpendicular to the longitudinalaxis of the bone plate.
 7. The bone plate of claim 6, further comprisingan apex formed between adjacent indentations, the apex aligned with atleast one of the plurality of outer apertures in a directionperpendicular to the longitudinal axis of the bone plate.
 8. The boneplate of claim 7, wherein each indentation extends inwardly toward thelongitudinal axis of the bone plate until reaching a maximum depth at abase, the base on a side of the bone plate aligned with the apex on anopposing side of the bone plate in a direction perpendicular to thelongitudinal axis of the bone plate.
 9. The bone plate of claim 1,wherein each of the plurality of outer apertures is sized to receive apolyaxial bone screw, the polyaxial bone screw adjustable between aperpendicular arrangement and an angled arrangement in the each of theplurality of outer apertures.
 10. A bone plate for use with a bonehaving a periprosthetic fracture, the bone plate having a longitudinalaxis that extends from a first end to a second end of the bone plate,the bone plate comprising: a planar bottom surface configured to facethe bone; a top surface opposite the bottom surface; a plurality of sidewalls joining the top and bottom surfaces; a plurality of outerapertures that extend through the bone plate from the top surface to thebottom surface, the plurality of outer apertures offset from thelongitudinal axis in a direction perpendicular to the longitudinal axis;and a plurality of indentations in the side walls, each indentationextending longitudinally between adjacent outer apertures to narrow thebone plate in a direction perpendicular to the longitudinal axis of thebone plate.
 11. The bone plate of claim 10, wherein a thickness of thebone plate measured between the top and bottom surfaces decreases towardthe first end of the bone plate.
 12. The bone plate of claim 10, furthercomprising a plurality of central apertures that extend through the boneplate from the top surface to the bottom surface, the plurality ofcentral apertures located along the longitudinal axis of the bone plate;13. The bone plate of claim 12, wherein the plurality of centralapertures extend from the first end to the second end of the bone plate.14. The bone plate of claim 12, wherein the plurality of outer aperturesare offset from the central apertures in a direction parallel to thelongitudinal axis of the bone plate.
 15. The bone plate of claim 12,wherein the plurality of outer apertures are arranged in twolongitudinal rows, a first longitudinal row extending along a first sideof the central apertures and a second longitudinal row extending along asecond side of the central apertures opposite the first side.
 16. Thebone plate of claim 10, further comprising an apex formed betweenadjacent indentations, the apex aligned with at least one of theplurality of outer apertures in a direction perpendicular to thelongitudinal axis of the bone plate.
 17. The bone plate of claim 16,wherein each indentation extends inwardly toward the longitudinal axisof the bone plate until reaching a maximum depth at a base, the base ona side of the bone plate aligned with the apex on an opposing side ofthe bone plate in a direction perpendicular to the longitudinal axis ofthe bone plate.
 18. The bone plate of claim 10, wherein each of theplurality of outer apertures is sized to receive a polyaxial bone screw,the polyaxial bone screw adjustable between a perpendicular arrangementand an angled arrangement in the each of the plurality of outerapertures.
 19. A method of repairing a bone having a periprostheticfracture, the bone including a prosthetic component implanted therein,the method comprising the steps of: providing a bone plate having alongitudinal axis that extends from a first end to a second end, thebone plate comprising a periprosthetic zone located at the first end ofthe bone plate, the periprosthetic zone comprising a plurality of outerapertures offset from the longitudinal axis in a direction perpendicularto the longitudinal axis, the plurality of outer apertures extendingthrough the bone plate substantially in parallel, the bone platenarrowing inwardly toward the longitudinal axis between adjacent outerapertures; and securing the bone plate onto the bone by inserting a bonescrew into one of the plurality of outer apertures while avoiding theprosthetic component.
 20. The method of claim 19, wherein the securingstep comprises pivoting the bone screw in the outer aperture andsecuring a locking cap onto the bone screw to lock the bone screw inplace.